Abstract: A marine drive includes an output gear including a beveled gear and a hub. A propeller shaft extends through the hub. A first bearing and an adjacent second bearing are located on the hub and support rotation of the output gear. The first and second bearings have inner races and outer races. An inner spacer is located on the hub and sandwiched between the respective inner races of the first and second bearings. An outer spacer is sandwiched between the respective outer races of the first and second bearings. A bearing carrier surrounds the propeller shaft and holds the first and second bearings therein by way of a press fit. The inner and outer spacers and the bearing carrier are dimensionally sized to provide a dimensional preload on the first and second bearings to maintain the output gear in alignment with the propeller shaft during operation of the marine drive.

Abstract: A marine drive includes an internal combustion engine that drives a propulsor into rotation to effect a thrust, and a transmission that shifts amongst a forward gear for a forward thrust, a reverse gear for a reverse thrust, and a neutral state for a zero thrust. The marine drive further includes a shift rod rotatable about its own axis to shift the transmission amongst forward, reverse, and neutral, and an actuator. The actuator includes an actuator motor that rotates an output shaft and a gear shaft that effectuates rotation of a shift rod. The output shaft is connected to a gear shaft through a first gearset such that rotation of the output shaft causes the rotation of the gear shaft, and the gear shaft is connected to the shift rod through a planetary gearset such that rotation of the gear shaft causes the rotation of the shift rod.

Abstract: A method of controlling reverse thrust by a propulsion device on a marine vessel includes determining that the propulsion device is situated to effectuate a reverse thrust and determining an initial trim position of the propulsion device. An engine RPM or an engine torque of the propulsion device is then controlled to effectuate a reverse thrust, and a trim position of the propulsion device is monitored. If a threshold increase in trim position from the initial trim position is detected at an increased engine RPM or an increased engine torque, then a reverse thrust limit is calculated based on the increased engine RPM or increased engine torque. The engine RPM of the propulsion device is then controlled so as not to exceed the reverse thrust limit while the propulsion device is effectuating the reverse thrust.

Abstract: A marine drive comprises an internal combustion engine that effectuates rotation of the driveshaft, a propulsor driven into rotation by the driveshaft so as to effect thrust, and a transmission that shifts amongst a forward gear, a reverse gear, and a neutral gear. The marine drive has a gear case housing on the bottom portion and a driveshaft housing around the driveshaft and positioned between the internal combustion engine and the gear case housing. The marine drive has a shift rod rotatable about its own axis, wherein rotation of the shift rod about its own axis shifts the transmission amongst the forward gear, the reverse gear, and the neutral gear. The marine drive also comprises an actuator positioned in the driveshaft housing that effectuates the rotation of the shift drive about its own axis.

Abstract: In one embodiment, an outboard marine engine comprises the internal combustion engine and a propulsor that is driven into rotation by the internal combustion engine so as to effect a thrust. The outboard marine engine further includes a transmission that shifts amongst a fourth gear wherein the thrust is forward thrust, a reverse gear wherein the thrust is a reverse thrust, and a neutral gear wherein the thrust is a zero thrust. The outboard marine engine further includes a shift rod that is rotatable about its own axis, wherein rotation of the shift rod about its own axis shifts the transmission amongst the forward gear, the reverse gear, and the neutral gear. An actuator operably connects to the internal combustion engine and causes rotation of a gear shaft. At least one gearset connects the gear shaft to the shift rod such that rotation of the gear shaft about its own axis rotates the shift rod about its own axis.

Abstract: An apparatus is for a changing gear in a marine propulsion system. A cam rotates about a first axis with a shift shaft. The cam has a body and an arm that radially extends from the body with respect to the first axis. A cam follower moves parallel to a second axis that is perpendicular to the first axis to cause movement of a clutch, thereby enacting a gear change. The cam follower defines a pocket that is elongated with respect to the second axis and a recess that extends from the pocket along a third axis that is perpendicular to the first and second axes. The cam is disposed in the pocket and the arm extends into the recess. During a constant rotation of the shift shaft in a first direction about the first axis, the cam follower moves with respect to the second axis to enact the gear change and also dwells with respect to the second axis.